Why? Your eye is drawn to motion with contrasting colors. Since the alcohol pad packet is often colored differently than the patient’s clothing or sheets, it makes the small motions of breathing much more visible to the observer. This is not a necessary step, and is generally used during learning activities, but there is no rule that says you cannot use this tip during the CNA exam! Since it makes it easier to see, and is not prohibited, why not give yourself every advantage?
An alcohol pad is small, lightweight, disposable and has a medical reputation. Patients often will assume you will be using it for a task later so they usually won’t even ask why you are putting it on their abdomen. Give it a try! Have someone lie down on a flat surface and observe their abdomen moving up and down. Then place an alcohol pad (or small slip of paper) on the volunteer’s abdomen and see how much easier it becomes!
This technique should be viewed like training wheels on a bike: useful while learning, but the student should progress beyond their use during regular clinical practice. However, this technique can be helpful when trying to view respirations on shallow breathers, those with apnea, near end of life, or other situations where the patient’s respirations may be difficult to visualize.